The present invention relates to reclosable plastic bags of the type having a zipper with mating interlocking members. More specifically, the present invention relates to an improved bag and method of producing such bag to include a spring portion so that the mouth of the bag normally assumes a wide open position when the interlocking members are disengaged.
The present invention relates to improvements in the package-making art and may be practiced in the manufacture of reclosable thermoplastic bags and packages of the kind that may be used for storage or as primary packaging for various consumer products. Such packages include a zipper means at the bag opening to facilitate reclosing of the bag to protect any remainder of the contents therein. The zipper may be slider-less or may include a slider to facilitate its operation.
The indicated art is fairly well developed but nevertheless remains open to improvements contributing to increased efficiency and ease of operation. In the prior art, the zipper could be formed integrally with the walls of the bag or attached in the form of a separate zipper strip. In either case, when the zipper is opened the individual profiles making up the zipper tend to remain together with one profile of the zipper resting on the other profile albeit with the interlocking elements of the profiles disengaged. This could make it difficult to fill or empty the bag.
Accordingly, the present invention relates to a reclosable bag and method for producing a reclosable plastic bag with an opening feature wherein when the interlocking elements of the zipper profiles are disengaged, the mouth of the bag assumes a wide open posture. To obtain the wide opening feature, a camber inducing strip is provided adjacent the bag top on one or both sides of the bag. The camber inducing strip may be co-extruded with the zipper, on one or both profiles of the zipper, positioned behind the interlocking elements or above or below the zipper interlocking elements.